This invention relates to an antistatic composition. In particular, it relates to a long-term antistatic composition.
The conventional antistatic products are fabricated by adding antistatic agent and using the conductive fillers like carbon black, conductive metal fiber, metal powder, or china powder to enhance their effective antistatic properties. The products described above have the advantages of being low-cost and having high-conductivity; however, the products are colorless and hard to dye. In addition, the products can not be spun, and the dust produced during the manufacturing process is distributed widely, resulting in serious air pollution and migration of the molded products (which is forbidden in a highly clean environment). Additionally, the antistatic products fabricated according to the methods described above generally have the disadvantages of being poor in color or having short-term antistatic properties. Moreover, the low M. W. ethylene oxide, or a compound with the functional group of ethylene glycol such as polyethylene glycol (PEG) or polyethylene oxide (PEO) or their copolymer (M. W.&lt;30000), is added as an antistatic agent to provide the products with the original resin color or dyeing ability. However, the drawbacks such products can be described as following: (a) the antistatic property of the molded products appears 24-72 hours after production; (b) cost are high; (c) the electrostatic charge has a brief dissipation time; and (d) the resistance of such products to water-washing is poor.
One antistatic fiber is disclosed in U.S. Pat. No. 3,475,898, wherein 3.about.15% by weight of an antistatic agent (possessing at least two hydroxyl group), for example olefin ether, with molecular weight more than 1000.about.30,000, is added to the polyamide. Then one fiber, with a diameter of about 0.05.about.1.5 .mu.m and a length of about 15 .mu.m is obtained after spinning to make an antistatic agent distribute along the longitude direction of fibers. The drawback of the antistatic fiber fabricated according to this invention described above is that the molecular weight of the antistatic reagent is much less than usually; in addition, the electrostatic charge has a very brief dissipation time, and washing-resistance is poor.
Another method for manufacturing a modified antistatic high molecular weight fiber and woven is disclosed in U.S. Pat. No. 5,364,582, wherein 0.8.about.2.5% by weight of low molecular weight amino olefin is added as an antistatic reagent to enhance the antistatic property, ultraviolet light resistance, dyeing ability and uptake properties of dyes. However, when this method is used, the physical properties of the fiber and the dissipation time of electrostatic charge are both poor.
One conventional conductive complex fiber fabricated by adding more than 30% by weight of Pyrol Polymer to enhance the conductive property of polyamide is disclosed in Japan TaiKo Patent No 4-65581; however, the product fabricated by this invention are darker in color and have poor physical properties.
Another conventional thermoplastic polyamide/polyether thin film is disclosed in EPO patent No.476895A2, wherein about 5.about.95% by weight of conductive thermoplastic polyamide/polyether copolymer, 40% by weight of polyamide and 1.about.5% by weight of ionomer are blend, then a thin film for package material is obtained by extrusion. The drawback of this thin film fabricated by this invention is that large amount of antistatic reagent is required which results in much higher costs.
Avoiding the drawbacks of the conventional antistatic material described above, this present invention provides a long-term antistatic composition using modified mold controlled techniques to develop an article with long-term antistatic, water-washing resistant and solvent-washing resistant properties.